In its latest round of financing, Uber attained a remarkable $17 billion valuation and raised an additional $1.2 billion of primary capital from investors, the company announced Friday.

With the $17 billion valuation, the car ride service now outpaces the worth of other multi-billion dollar Silicon Valley start-ups like Airbnb and Dropbox, as well as other successful traditional car rental companies like Hertz and Avis Budget. Indeed, Uber’s worth now places it closer to the rarefied air of such celebrated tech firms as Twitter and LinkedIn, The New York Times reports.

“It’s remarkable that it was only four years ago this week Uber started operations in SF,” said Uber CEO Travis Kalanick. “Today, we are operating in 128 cities in 37 countries around the world with hundreds of thousands of transportation providers and millions of consumers connecting to our platform.”

Kalanick revealed to The Wall Street Journal Friday that the service doubles in revenue every six months, while the raw number of trips increases at an even greater rate. Being privately held, Uber is under no legal obligation to disclose its financials.

“We’re at least doubling every six months,” said Kalanick. “That’s revenue. If you look at [the number of] trips, because we’re going into lower and lower-cost products, the growth on trips is like 5, 6x.”

Kalanick additionally shed some light on the company’s initial moves into the logistics market, most notably with the Manhattan courier service Uber Rush.

“Uber Rush is a month and a half, two months old, it’s super early,” he said. “You got to work the product, get the operations down, processes, technology, etc. We’re very bullish but that was not part of the pitch for this fundraise…If the logistics business works out, that’s icing on the cake.”